Satellites from low Earth orbit (LEO) are usually only able to send their data to the ground station if they are within its range. The use of a geostationary satellite (GEO) such as EDRS-C as a relay enables much longer radio transmission times.

Airbus is the industrial prime contractor for the European Data Relay System (EDRS). In April, 2019, before being shipped, the satellite was put through its paces at Airbus' antenna test centre in Ottobrunn. OHB System AG in Bremen developed and built the EDRS-C satellite.

The acoustic tests for EDRS-C took place in December 2018 at IABG in Ottobrunn.

Credit:
OHB System AG.

The European Data Relay System (EDRS) is setting new standards for the rapid transfer of large quantities of data from space to Earth.

At 21:30 CEST (16:30 local time) on 6 August 2019, the first dedicated EDRS satellite, and the second node in its network, lifted off from the European spaceport in Kourou, French Guiana, on board an Ariane 5 launch vehicle and is on its way to its target geostationary orbit at about 36,000 kilometres above Earth. The satellite separated from the launch vehicle 33 minutes after launch at 22:03 CEST. First contact with EDRS-C followed at 22:10 CEST.

EDRS-C will primarily be used for the rapid transfer of high-rate Earth observation data. In this way, the satellite ensures that data acquired worldwide by the Sentinel satellites of the European Copernicus Earth observation programme reach the users even faster. Its core element is the Laser Communications Terminal (LCT), which was developed and manufactured mainly in Germany.

Focus: Digitalisation, space, Big Data

With the launch of the first EDRS-C communications satellite on 6 August 2019, a milestone has been reached for the EDRS system. EDRS is a globally unique network of geostationary relay satellites that can deliver data volumes of up to 1.8 gigabits per second to Earth with minimal delay using laser communications. The system is a public-private partnership between the European Space Agency (ESA) and the Prime Contractor, Airbus. With an investment of approximately 235 million euro (61 percent), Germany is the main contributor to this ESA programme. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) Space Administration manages this contribution, using funds made available by the Federal Ministry of Economic Affairs and Energy (BMWi), on behalf of the German Federal Government. The EDRS-C satellite was designed, built and tested in Germany. The satellite weighs just under 3.2 tonnes and has a planned service life of 15 years. The German Space Operations Center located at the DLR site in Oberpfaffenhofen, has been contracted by Airbus to control the EDRS-C satellite and its payload on their behalf.

“In the past, satellites were only linked to one or more ground stations. With the development of EDRS, we are making a paradigm shift towards an optically networked satellite infrastructure. With greater security and much higher bandwidth, EDRS enables the transmission of images and data in near-real time,” says Walther Pelzer, DLR Executive Board Member responsible for the Space Administration, who also adds: "EDRS-C incorporates a great deal of high technology from Germany.” Earth observation satellites are providing an increasingly accurate picture of Earth, its environment and its climate. However, they are also producing more and more data that must be made available very quickly so that they can optimally inform and accompany decision-making processes.

The way in which this ‘data superhighway’ will work was demonstrated at a live presentation in Brussels on 10 July 2019. Within a few seconds, data were transmitted from one of the European Sentinel-1 Earth observation satellites to the ground via laser, tracking ships and possible oil leaks. Under normal circumstances, this transfer would take several hours..

The programme’s first communications node, EDRS-A, was launched on 29 January 2016 and provides relay services for data transfer from four Sentinel satellites belonging to the EU Copernicus Earth observation programme. The satellites use EDRS-A services daily and, to date, more than 23,000 inter-satellite links have been successfully used to transfer data to Earth. EDRS-C will now double this capacity.

Following a test and validation phase, the system should be fully operational with EDRS-C by the end of 2019. Technological development has continued alongside the construction and launch of the EDRS satellites, with Germany supporting the further development of the LCT technology as part of ESA’s ARTES ScyLight programmes. Among other things, the data rate of the terminal will be increased from 1.8 to 3.6 gigabits per second, and the potential connection distance increased from 40,000 to 80,000 kilometres.